There are two kinds of traffic. One from fellow Hubbers. That will get a new Hub some initial traffic which will soon drop off drastically. The other type is from the search engines. That should start off slow and build to a more or less steady level. Maybe some gradual decline over time. But you get that latter type only if you have a topic that people outside of Hub Pages are actually searching for.
Bottom line, you need to get links so that Google, etc., give you some love.